MONTPELIER, Vt. (AP) – The National Weather Service issued a flood watch Wednesday for Vermont and northern New York state, saying warming temperatures and rain could trigger river rises – including the Winooski River.

The flood watch, which was posted at 9:33 a.m., is in effect through 11 a.m. today, is a lower level advisory than a flood warning. It came after a night in which temperatures hovered between 45 and 50 degrees, accelerating snowmelt on the ice-jammed river, which flooded Montpelier in 1992.

“The Winooski at Montpelier has been of particular concern this year, and will bear watching through (this) morning,” the Weather Service said.

Greg Hanson, a hydrologist for the Weather Service in South Burlington, said people in Montpelier needed a “heightened awareness” of the river’s condition.

“I wouldn’t use the words “imminent’ or “critical’ or anything like that. We’d use a (flood) warning in that case. Here, there’s heightened risk.”

The river, which has opened up slightly during the week, rose about 1.5 feet early Wednesday but later dropped back down, according to City Manager William Fraser. A construction crane lowering a steel I-beam onto the river ice continued breaking up portions Wednesday.

But the Weather Service forecasted steady rain Wednesday night, and the combination of melting and precipitation was expected to cause a three- to four-foot rise in the river, which would still be below flood stage, according to the U.S. Geological Survey.

The rise could be enough to break up ice and lead to flooding, officials said.

“It’s fair to say that in this week’s weather cycle, this is the highest-risk evening,” Fraser said late Wednesday. “If we can get past this rain tonight, we’ll be good.”

Merchants and homeowners, meanwhile, continued their preparation.

A self-serve sandbag operation operated in front of City Hall, with the Vermont National Guard filling the sandbags and delivering them to the plaza in front, where they were available for the taking.

Most downtown businesses have fortified their storefronts with sandbags, plywood or both.

“We’re doing all we can do,” said Kathy Berry, co-owner of Pinky’s on State, a sandwich shop. “If it’s going to happen, it’s going to happen. What are you going to do? We’ll serve soggy sandwiches.”

City and state officials planned a 4 a.m. conference call to assess the condition of the river and make a decision about whether to close state government offices today.

With about 2,100 workers employed at various sites around the capital, the decision had to be made early, according to Administration Secretary Mike Smith.